Assessment of Seasonal and Annual Rainfall Trends and Variability in Sharjah City, UAE
Table 4
Short-term and long-term seasonal trend analysis by linear regression and Mann-Kendell tests(one-tailed with 5% significance interval).
Method
Linear regression trend test
Mann-Kendall trend test
Period
1934–1976
1977–2014
1986–2014
1934–1976
1977–2014
1986–2014
LRS
LRS
LRS
SS
value
SS
value
SS
value
mm/yr
mm/yr
mm/yr
mm/yr
= 5%
mm/yr
= 5%
mm/yr
= 5%
Winter
−0.29
−1.20
−2.93
−0.46
0.052
−1.18
0.004
−2.98
<0.0001
Spring
0.24
−0.05
0.10
0.00
0.014
0.0004
0.322
0.00
0.918
Summer
0.02
0.23
0.11
0.00
0.002
0.00
0.809
0.00
0.003
Autumn
−0.29
0.08
0.19
0.00
0.213
0.00
<0.0001
0.00
0.000
Period
1934–1964
1960–1990
1984–2014
1934–1964
1960–1990
1984–2014
Winter
−0.81
2.05
−1.50
−0.96
0.003
1.82
<0.0001
−1.46
0.026
Spring
1.30
−0.56
0.16
0.0006
0.019
0.00
0.822
0.00
0.102
Summer
0.12
−0.04
0.16
0.0005
<0.0001
0.00
0.326
0.00
0.242
Autumn
−0.02
−0.06
0.24
0.00
<0.0001
0.00
0.122
0.00
<0.0001
LRS: linear regression slope; SS: Sen’s slope; negative and positive signs of slope indicate a decreasing trend and an increasing trend, respectively. All tests’ slopes are in mm/year.
